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Digital a pain the arse!


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I have line of sight to both North Head and Kings Cross, I could walk to the building at Kings Cross in about 15 mins, but still have reception issues.

It's not constant, I go weeks on end with all channels working fine, then everything just goes crazy (7, 9, 10 are the main offenders)

Signal 100%, quality 83%, but still it screws me around, with chirp/freeze action.

Digital is nice, but I want to watch TV, not issues with digital reception

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quality 83%.... very bad!! Normally it is the other way around, signal 80%, quality 100%.

I am guessing that you are on a distribution system of some sort, and guessing that the RF distribution amplifier is as noisy as hell. So you are getting tonnes of signal level, but the digital RF carrier is getting messed up quite a bit (to get only 80% quality!) This is often the case if the gain is turned up too much on a masthead or distribution amp, it introduces a bunch of non-linearities which really knocks the digital RF signal around quite badly.

You have to aim for 100% quality, and ignore the signal strength (to some extent. Obviously it is handy to see relative readings as you start playing with gains etc).

If you don't have access to the amp, then I suggest experimenting with rabbits ears or one of those christmas tree fricarros or whatever they are called. The guy posts in these forums regularly, the picture of his "disguised" antenna must have been viewed by thousands.

Edit: This thread may help: http://www.dtvforum.info/index.php?showtopic=9965&hl=

Regards

Edited by tonymy01
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You have to take those meter readings on the STB with a pinch of salt - they're not always very accurate (from memory my first cheapo STB had the quality & strength readings opposite to what my Toppy reports).

You may even find your problem is too much signal and you are overloading your STB - like Tony said try rabbit ears or an attenuator (Jaycar, DSE). Unfortunately without getting a professional in who has the proper equipment you can only guess at the problem and try different things to remedy it. I'd also make sure your flylead to the STB is made from quad shield coax cable (not the crappy moulded cheap & nasty leads) - I found when I was using one of those originally it was picking interference up from the remote and who knows what else.

Cheers,

Bruiser

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Thanks, I was rather annoyed last night, not the first time I turned the TV on to watch something and had to battle to get it stable.

Funny enough, everything is fine again today, all channels are working well. On a side note, I live on level 35 in the Sydney CBD (east facing) so taxi's etc should not be an issue.

I've tried rabbit ears, amp-UHF/rabbit ears, but it seems to change too much.

Scan and everything is fine, come back week later and you battle to get the channel decent.

Nothing changes, so what is the deal? I had everything perfect, should it not continue to be perfect?

Aerial on the roof Level 45 and has been digital approved, points to KingsCross, they also have a spliter off to North Head.

Cable from the wall is 1m, standard lead, and behind the bookcase, not in the open.

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Thanks, I was rather annoyed last night, not the first time I turned the TV on to watch something and had to battle to get it stable.

Funny enough, everything is fine again today, all channels are working well. On a side note, I live on level 35 in the Sydney CBD (east facing) so taxi's etc should not be an issue.

I've tried rabbit ears, amp-UHF/rabbit ears, but it seems to change too much.

Scan and everything is fine, come back week later and you battle to get the channel decent.

Nothing changes, so what is the deal? I had everything perfect, should it not continue to be perfect?

Aerial on the roof Level 45 and has been digital approved, points to KingsCross, they also have a spliter off to North Head.

Cable from the wall is 1m, standard lead, and behind the bookcase, not in the open.

As Bruiser said: Try a $10 attenuator! Many STBs do worse with a strong signal than a weak one. Good news for our country cousins, but bad news in the city.

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Don't get me wrong, but if the old service is going to be turned off, people like me and far from it, will have the same issues.

Throwing money at buying aerials/cables etc is not the solution.

The service works fine, then screws up, even my friend out in Auburn has the same issue, works fine for weeks, then just dies.

Something is wrong here, and it's not the consumer.

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Throwing money at buying aerials/cables etc is not the solution.

Wabby,

Unfortunately unless you get a professional out who can read the signal and determine what is going on, all you can really do yourself is experiment with some of the suggestions here or in the other posts in this forum.

Cable from the wall is 1m, standard lead, and behind the bookcase, not in the open.

Again, those crappy moulded fly leads are dodgy - try flexing/moving your lead in different sections (including near the plug) - if the picture on your tv breaks up or fluctuates, then it's a sure sign. Also, I'm not sure a bookcase offers much protection from electrical interference, etc.

Finally, I've spent at least as much on my antenna/cabling system as I have on my STB (Topfield), and I still have problems - it's definately going to be fun to watch when they switch off the analogue...

Cheers,

Bruiser

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Wabby,

The most likely cause of your problem is that North Head and Kings Cross use exactly the same transmission channels as each other. This is because there is not enough channels to double up on every station from the Illawarra to the Hunter Valley.

The channels used are Band 4+ about 248 mm

Typical antennas

Hills TMX14 8-13 dB

Hills TMX20 8.5-15 dB

http://www.hillsantenna.com.au/catalog/UHFAntenna.pdf

Matchmaster 02MM-DR18B ≤14 dB

http://www.matchmaster.com.au/Pdf/spec-on-dr18ab.pdf (B4, B4+)

These antennas are very directional and should be mounted horizontally and pointed at the Elan Building top.

Kings Cross

Analog ABN 46 SBS 58 ATN 49 TCN 52 TEN 55

Digital ABN (2) 30 SBS (3) 34 ATN (7) 48 TCN (9) 33 TEN (1) 45 Spare 29, 35

A band 5 antenna is required for analog and is not suitable for digital channels which are lower in channel number. Also Master Antenna Systems used in units often have an amplifier for each channel. Since digital uses different channels they may not be reticulated.

AlanH

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  • 3 weeks later...

Wabby,

I fully understand your frustration. I have been using a STB now for just over a month and it has been a huge 'pain in the arse', as you say.

I was watching TV last night and every chanel was fine. Then, for no apparent reason, I lost every chanel except chanel 7.

I simply couldn't work out why! No electronic devices were turned on or off, no doors were opened, I didn't even move from where I was sitting.

At least with analog, I could get 85%+ quality on every chanel. Now, it is all or nothing.

*sigh*

Of course, people will recommend this or that or a professional set-up, or a new arial, or whatever. But the simple fact is that free-to-air digital TV promises the world and delivers a dodgy service.

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But the simple fact is that free-to-air digital TV promises the world and delivers a dodgy service.

Probably not quite true - obviously some people have no or few problems, while others suffer from bad reception or other problems. Like with anolog now, except that a snowy anolog didn't seem to bug me like interference on the digital signal does (mind you, there's no way I'd go back now). Mrbplus, I certainly agree it's a pain in the arse trying to track down interference issues, the problem is you are only guessing without getting someone out to take the proper digital signal readings. And even then, who's to say your neighbour's power drill, or someone's cb transmitter down the road, or a passing car, or whatever, isn't going to affect your reception?

and no dodgy cheap losing channel probs (you get what you pay for!)

Tony, not always the case either - I have a Topfield, and have spent at least the same on my antenna system, and still suffer from the ever present glitches. Not everyone enjoys line of sight, interference free digital tv (unfortunately)...

Cheers,

Bruiser

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